Computers and their associated video display terminals (computer monitor screens) are used extensively in the workplace in association with many tasks, such as accounting, word processing, and the like. Individuals who use computers are sometimes required to use them continuously for long periods of time.
Prolonged viewing of computer monitor screens often results in eyestrain, burning sensations in the eyes, fatigue and headaches. Eyestrain and the burning sensation associated with prolonged viewing appear to be caused both by glare and by the eye muscles of the viewer attempting to converge the eyes to the near point image on the screen. It has been determined that, when an individual looks straight ahead, for example, at a computer monitor screen, the natural tendency of the eye muscles is to cause the eyes to diverge for distance vision. Therefore, in order to focus on a computer monitor screen at the normal viewing distance of from 18 to 25 inches while looking straight ahead, the eye muscles are strained to converge the eyes. Conversely, when an individual looks downward at a 20.degree.-30.degree.angle, or so, the eyes naturally converge for near vision. In addition to eyestrain caused by attempting to focus on a computer monitor, persons using bifocals are forced to tilt their heads up toward the ceiling in order to view the screen through their bifocal segment. Tilting the head is uncomfortable and causes fatigue. Eyestrain and fatigue can result in headaches.
In addition to complaints of eyestrain, fatigue and headaches, the cathode ray tubes which are incorporated into computer monitors emit electromagnetic radiation which may be harmful to a user when the user is exposed to such radiation for continuous prolonged periods of time.
There is, therefore, a need for a device configured to reduce the glare associated with viewing a computer monitor screen and disposed to be positioned so that the operator can read the information being displayed while looking downwardly, for example, at an angle of 20.degree.-30.degree., instead of straight ahead. It is also desired to enhance the computer operator's safety by providing a viewing device that is configured to reduce the problem of longterm exposure to radiation from video display terminals.